This invention relates to a material-handling vehicle of the kind, hereinafter referred to as the xe2x80x9ckind specifiedxe2x80x9d, including a structure having, ground engageable propulsion means, a loader arm mounted for up and down swinging movement, an operator""s cab, an engine having an output to provide power for said movement of the loader arm and propulsion of the vehicle and drive to connect the output to the ground engageable propulsion means to propel the vehicle.
One vehicle of the kind specified is disclosed in U.S. Pat. No. Re-30,021. In this machine, which is relatively large, the loader arm is substantially horizontal but is angled downwardly in the forward direction, is partly accommodated in a well provided between the cab and a load carrying platform disposed on the opposite side of the loader arm to the operator""s cab. As a result the loader arm, in a fully lowered position, is disposed below a horizontal plane containing the top of a steering wheel in the operator""s cab so that the driver""s vision is substantially unobstructed. This vehicle is sufficiently large that an upright engine to provide power for swinging movement of the arm and propulsion of the vehicle can be accommodated beneath the well on the centre line of the vehicle.
WO-A-89/00972, CA-A-2,009,968 and EP-A-0,656,315 discloses vehicles of the kind specified in which a loader arm, in a fully lowered position, is similarly substantially horizontal although the precise angle of the loader arm varies in the three above referred to specifications, is at least partly accommodated in a well disposed between the operator""s cab and a housing in which the engine is disposed. The loader arm is disposed so it does not at least substantially interfere with the view of the operator in this direction.
A vehicle configuration as disclosed in these three references, in which the engine is offset to be on the opposite side of the loader arm to the cab, enables the vehicle to be made smaller than the vehicle of U.S. Pat. No. Re-30021 and enables the overall height of the vehicle to be reduced.
DE-A-2,739,537 discloses another vehicle of the kind specified but in which the loader arm, in its lowered position is disposed so that the loader arm is entirely above the level of the top of the engine and its associated housing. Accordingly the vehicle is unprovided with any well so that in a lowered position the loader arm extends alongside the operator s cab substantially above the bottom of a side window therein so that the driver""s view transversely of the vehicle is obstructed.
All the above mentioned vehicles suffer from one or other disadvantage.
In U.S. Pat. No. Re-30,021 because of the disposition of the engine underneath the loader arm the operator""s cab is required to be relatively high so that the operator can still see over the top of the loader arm whilst providing sufficient space beneath the loader arm for the accommodation of the engine and access to the engine is restricted.
In WO-A-89/00,972 the engine is arranged with the crank shaft thereof longitudinally of the vehicle. Access to the side of the engine adjacent to the cab is obstructed by the presence of the cab and the wheel base of the vehicle must be relatively large to accommodate the longitudinal extent of the engine between the wheels. A short wheel base is desirable as it improves maneuverability of the vehicle, which is important for operating in confined spaces. In a vehicle of the type described in this specification and as marketed by the applicants in respect of WO-A-89/00,972a hydrostatic drive is provided to transfer drive transversely from the engine towards the ground engageable means.
In CA-A-2,009,968 the engine is also arranged with its crank shaft longitudinally of the vehicle and so suffers from the disadvantages mentioned in the preceding paragraph. In this case a mechanical drive is provided to transfer drive transversely from the engine towards the ground engageable means.
DD A 240 869 discloses a drive for a mechanical handling vehicle of the kind specified in which the engine is disposed with its crank shaft transversely of the vehicle and an angle gear drive is provided to transfer drive through 90xc2x0 from the engine towards the ground engageable means.
In EP-A-0,656,316 the engine is also disposed with its crank shaft transversely to the vehicle and an angle gear drive is provided to transfer drive through 90xc2x0 from the engine towards the ground engageable means.
These vehicles suffer from the disadvantage of the need to provide a relatively expensive angle gear drive and associated engineering problems to turn the drive through 90xc2x0.
In DE-A-2,739,537 the driver""s view transversely across the vehicle is obstructed because of the absence of a well to accommodate the loader arm.
An object of the present invention is to provide a material-handling vehicle of the kind specified whereby the above mentioned problems are overcome or are reduced.
According to the present invention we provide a material handling vehicle of the kind specified wherein the output of the engine is kinematically connected to a change speed gear box which drives at least a rear axle of the vehicle, at least one of the engine and the change speed gear box being connected to the rear axle to provide a sub-assembly and said sub-assembly being mounted on said structure for pivotal movement about an axis which lies in, or is parallel to, a plane which contains the longitudinal axis of the vehicle.
The engine may be disposed to the rear of the rear axle.
The gear box may be disposed to the front of the rear axle.
Said at least one of the engine and the change speed gear box may be connected to the rear axle by virtue of being mutually interconnected.
Alternatively said at least one of the engine and the change speed gear box may be connected to the rear axle by means of an intermediate member.
The intermediate member may comprise a frame to which the axle is connected and to which said at least one of the engine and change speed gear box is connected.
The engine and the change speed gear box and the real axle may be connected together to provide the sub-assembly.
The sub-assembly may comprise a mounting member.
The mounting member may be pivotally connected to said structure for rotation about said axis.
At least one of the engine, gear box and rear axle may be connected to the mounting member.
The change speed gear box may be provided with at least one output which is kinematically connected to said ground engageable propulsion means.
The change speed gear box may have two outputs.
The vehicle may comprise a front axle and a rear axle, ground engageable propulsion means mounted on the axles and the propulsion means of at least one of said axles being connected to said at least one output of the gearbox.
At least one of said axles may have a differential which is connected to said output of the gearbox.
The front axle may be connected to a front output of the gear box by a shaft which may have a universal joint at least at one end.
The rear axle of the vehicle may be connected to a rear output of the gear box.
The rear output of the gear box may comprise a shaft which extends to said rear axle.
The rear axle may be connected to said rear output by means of a shaft which drives a pinion gear which meshes with a crown-wheel gear of the differential.
A clutch, torque converter or the like may be provided between the engine and the ground engageable propulsion means.
The sub-assembly may be provided with a clutch or torque converter or the like.
The clutch or torque converter or the like may be provided on the input side of the sub-assembly.
The vehicle may comprise a chassis having a pair of spaced longitudinally extending frame members.
The frame members may be parallel to each other.
The frame members may be provided with a pair of spaced transversely extending members which carry a pivot member whereby said mounting member is mounted on the structure for rotation about said axis.
The engine may be disposed so as to lie substantially between spaced vertical planes containing said frame members.
Compliant mounts may be provided between at least the engine and the chassis.
The longitudinal axis of the loader arm may extend forwardly parallel to a vertical plane containing a longitudinal axis of the vehicle.
The structure may have a front end and a real end with said longitudinal axis of the vehicle extending therebetween and the ground engageable propulsion means being disposed equi-distant from, and on opposite sides of, said longitudinal axis.
The loader arm may be pivotally mounted towards the rear of the machine about a horizontal axis.
The loader arm may carry a material handling implement at its front end so that the material handling implement is disposed in front of the front of the structure when the arm is in its lowermost position.
The cab may have a side window which faces transversely across the vehicle at right angles to the longitudinal axis of the loader arm.
The top of the loader arm in a fully lowered position and at a location alongside the top of a steering wheel in the operator""s cab may be disposed wholly or substantially wholly below a horizontal plane which is not more than 1 meter, or preferably not more than 0.5. meter, above the top of a steering wheel so that the driver""s vision is substantially unobstructed by the loader arm.
If desired the top of the boom at said location may be wholly or substantially wholly below a horizontal plane containing the top of the steering wheel.
The loader arm may be telescopic in the direction of the longitudinal axis of the loader arm.
The longitudinal axis of the loader arm may lie in a substantially horizontal plane when the loader arm is in a position in which the implement engages a horizontal plane on which the ground engageable propulsion means are supported and, if the loader arm is telescopic, the loader arm is fully retracted.
The ground engageable propulsion means may be driven from the engine wholly via a mechanical transmission or a hydrokinetic transmission.
The ground engageable propulsion means may comprise a pair of ground engageable wheels disposed adjacent the front of the structure and a pair of rear ground engageable wheels adjacent the rear of the structure.
The wheels of the front pair may be driven from the first output of the gear box whilst the wheels of the rear pair may be driven by the rear output of the gear box.
Where the gear box and the rear axle are mutually interconnected the shaft which connects the rear output of the gear box to the rear axle may provide a direct drive.
Alternatively, the gear box may be spaced forwardly of the rear axle and mounted on the chassis.
In this case the shaft which connects the rear output of the gear box to the rear axle may be provided with a universal joint at least at one end.
In this case the gear box may have an input which is connected to the engine by a shaft having, at least at one end, a universal joint.
Preferably the shaft which is connected to the rear output of the gear box or the shaft which is connected to the input of the gear box has a universal joint at each end and means may be provided whereby the separation of the gear box from the rear axle or the engine respectively is variable.
Where at least one of the engine and gear box is connected to the rear axle to provide a sub-assembly through an intermediate member, such as a frame, the shaft which connects the rear output of the gear box to the rear axle may be external to a case of the gear box and the rear axle. The input of the gear box may be connected to the engine by a shaft which is external to the casing of the gear box and of the engine.